Acceleration of impairment of endothelium-dependent responses under poor runoff conditions in canine autogenous vein grafts.
OBJECTIVE
To assess the effects of changes in shear stress on endothelium-dependent responses.


METHODS
Autologous vein grafts were implanted in poor or normal distal runoff limbs of 10 mongrel dogs. Six weeks after grafting the vein grafts were removed, cut into rings, and suspended in organ chambers for isometric tension recording.


RESULTS
The average value of intimal thickening was 110.7 +/- 45.2 microns in poor runoff limbs and 65.5 +/- 27.9 microns in control limbs, respectively. There was a significant difference between the two groups. Acetylcholine caused comparable endothelium-independent contractions in both groups. In the control group, adenosine diphosphate, thrombin and A23187 caused endothelium-dependent relaxations. In the poor runoff group, the endothelium-dependent relaxations caused by adenosine diphosphate and thrombin were impaired, while A23187 caused comparable endothelium-dependent relaxations. Direct relaxations in response to sodium nitroprusside were comparable between the two groups.


CONCLUSIONS
This dysfunction of the endothelium under conditions of abnormal flow may accelerate intimal thickening of the vein graft and result in late graft failure.
Komori
K
K
Second Department of Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Yamamura
S
S
Ishida
M
M
Matsumoto
T
T
Kuma
S
S
Eguchi
D
D
Yonemitsu
Y
Y
Onohara
T
T
Sugimachi
K
K
D000818:Animals; D004285:Dogs; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D005263:Femoral Artery / Q000601:surgery; D005268:Femoral Vein / Q000473:pathology / Q000503:physiopathology / Q000637:transplantation*; D006614:Hindlimb; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000503:physiopathology; D009569:Nitric Oxide / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D014182:Transplantation, Autologous; D017539:Tunica Intima / Q000473:pathology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009569:Nitric Oxide